SSFP version?

I recently purchased another SSFP to try out, but I am not sure if its a mk1, mk2 or something in between. It looks like this (not my picture):I presume that its a mk1, but the mk1 seems to look like this (not my picture):I have replaced a mk3, and it is actually performing better on my line, resulting in lower amount of errors in both directions, and the SNR per tone differing between the two, with more SNR in the lower frequencies, but the mk3 having more SNR in the higher frequencies, but I would rather have higher SNR in the low, as the higher frequencies tend to be affected by noise more.mk3:mk unknown:The manufacture date on the packaging is 1313.